Apparatus for direct injection molded closure

ABSTRACT

A form, fill and seal packaging machine for forming, filling and sealing a carton, molds a closure directly onto the carton. The machine includes a carton erection station adapted to receive a carton in a generally flat form and to erect the flat form carton into a tubular form defining an internal carton region. A direct injection molding station has an internal mold tool and an external mold tool. The internal mold tool is configured for receipt within the internal carton region and the internal mold tool and the external mold tool are configured to receive and clamp the carton therebetween. The direct injection molding station further includes a polymer injection system for injecting polymer from a location external of the carton to the internal mold tool. The closure is directly molded in place on the carton. A mold tool set, a method for carrying out the molding and a closure molded thereby are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.10/124,968, filed Apr. 18, 2002 now U.S. Pat. No. 6,837,697, which is adivisional application of U.S. patent application Ser. No. 09/594,247,filed Jun. 15, 2000, now U.S. Pat. No. 6,467,238.

FIELD OF THE INVENTION

This invention pertains to molded closures for containers. Moreparticularly, this invention pertains to directly injection molding aclosure onto a container.

BACKGROUND OF THE INVENTION

Consumers have come to recognize and appreciate resealable closures forcontainers to store, for example, liquid food products and the like.These resealable closures permit ready access to the product whileproviding the ability to reseal the container to prolong the life andfreshness of the product. Typically, the containers or cartons areformed from a composite of paperboard material having one or morepolymer coatings or layers to establish a liquid impervious structure.

In known containers having such closures, the closures, which are formedin a separate process and transported to the packaging process, areconventionally affixed to the containers as part of the overall form,fill and seal operation. Typically, the closures are affixed to thepartially erected carton prior to filling the carton with product. Oneknown method for affixing the closure to the carton uses an ultrasonicwelding process. In this process, the carton is partially erected andthe closure is brought into contact with the carton, overlying anopening in the carton. Subsequently, an anvil is placed against thecarton material and an ultrasonic horn is brought into contact with aflange of the closure. The ultrasonic horn is actuated whichultrasonically welds the flange to the carton material.

Another method for affixing closures to cartons uses an inductionheating process. In this process, again, an anvil is placed on thecarton material and an induction sealing head is brought into contactwith the flange. A current is induced in the induction sealing headwhich, again, results in welding the flange to the carton.

While these methods for affixing the closures to cartons work well forsealing pre-formed or pre-molded closures to containers, and while theydo facilitate maintaining product freshness and container resealability,there are nevertheless drawbacks. For example, closure sourcing couldhave a significant adverse impact on product manufacture. That is,bottlers or dairies must maintain high inventories of closures to assurethat a sufficient quantity is on-hand during the bottling operation,Typically, the closures are provided by a closure manufacturer orsupplier. Thus, if the manufacturer or supplier cannot meet the requiredsupply, product production (e.g., packaging) may have to be slowed orstopped until the required volume of closures can be obtained.

In addition, equipment is necessary for transporting and affixing theclosures to the cartons. With respect to this equipment, components arenecessary to transport the caps from a storage area to the carton andto, perhaps, properly orient the closures at the carton. Additionalmachine components are also needed to support the closure at the cartonand to seal the closure to the carton.

Thus, as will be readily recognized, while such closures providenumerous benefits and advantages over known folded gable top spoutarrangements, these closures can be rather costly, and may be too costlyfor use in lesser expensive products.

Accordingly, there is exists a need for an apparatus and method forproviding resealable closures on cartons. Desirably, such an apparatusand method eliminates a packagers reliance on a closure supplier. Moredesirably, such an apparatus and method allows for eliminating thoseportions of a form, fill and packaging machine that are related toaffixing a closure, such as by welding, to a carton.

SUMMARY OF THE INVENTION

A form, fill and seal packaging machine for forming, filling and sealinga carton molds a closure directly onto the carton. The machine includesa carton erection station that is adapted to receive a carton in agenerally flat form and erect the flat form carton into a tubular formdefining an internal carton region.

A direct injection molding station has an internal mold tool and anexternal mold tool. In a preferred embodiment, the internal tool isfixedly mounted and the external tool is configured to move between afirst position in which the external tool is disengaged from theinternal tool and a second position in which the external tool isengaged with the internal tool with the carton disposed therebetween. Ina most preferred embodiment, the external tool is formed having firstand second portions configured to move toward one another when theexternal tool moves to the second position, and away from one anotherwhen the external tools moves to the first position.

The internal mold tool is configured for receipt within the internalcarton region. The internal mold tool and the external mold tools areconfigured to receive and clamp the carton therebetween.

The direct injection molding station further includes a polymerinjection system for injecting polymer from a location external of thecarton to the internal mold tool, thus is directly molding a closure inplace on the carton.

The machine further includes a filling station for filling the cartonand a sealing station for forming a seal on the carton.

The polymer injection system can be configured to include a chargingcylinder and an injection cylinder in series with one another. Thecharging cylinder provides a feed of polymer to the injection cylinder.Most preferably, the charging cylinder and the injection are in opposedrelation to one another and are separated by a non-return valve.

In a preferred embodiment, the machine includes a sprue bushing in flowcommunication with the injection cylinder and a needle reciprocablewithin the sprue bushing for initiating and terminating flow of polymerto the internal tool.

To effect proper temperature control of the tools and the closure duringformation, the internal and external mold tools include coolingchannels. Heat transfer is maximized in an internal tool having coolingchannels having a V-shaped configuration.

In the machine, a frame is mountable to the packaging machine, and amandrel is mounted to the frame, on which the carton is mounted, andsecured by the molding tools, during molding of the closure. Preferably,the internal mold tool is mounted to the mandrel.

A method for forming a closure on a carton blank in a tubular form, inwhich the carton blank is formed from a composite material having apolymer layer on at least one side thereof, includes the steps providinga fixed mold tool defining a portion of a mold cavity therein, the moldtool being in flow communication with a polymer injection system,positioning the carton blank adjacent and engaged with the internaltool, the carton blank being in an at least partially erected statehaving a tubular form, and providing a movable tool defining anotherportion of the mold cavity therein, the fixed tool mold cavity and themovable tool mold cavity defining a desired closure configuration

The method further includes the steps of engaging the movable tool withthe carton blank on an opposing side of the carton blank from theinternal tool, pressing the movable tool to the carton blank and thefixed tool, injecting a polymer into the mold cavity to form the desiredclosure, and releasing the carton with the closure molded thereon.

Other features and advantages of the present invention will be apparentfrom the following detailed description, the accompanying drawings, andthe appended claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a form, fill and seal packaging machinehaving a direct injection molded closure (“DIMC”) section embodying theprinciples of the present invention mounted thereto;

FIG. 2 is an enlarged, partial perspective view of the machine of FIG. 1illustrating the position of the DIMC section relative to the otherportions of the machine;

FIG. 3 is a perspective view of the molding components of the DIMCstation, the molding components being shown with an exemplary cartonpositioned for having a closure molded thereon;

FIG. 4 is an exploded view of the molding components shown in FIG. 4;

FIGS. 5 through 7 are partial exploded views of the molding componentsof FIGS. 3 and 4;

FIG. 8 is a partial cross-sectional view of the molding components shownthe needle positioned within the sprue bushing and the sprue bushingpositioned within the internal mold tool;

FIG. 9 is an enlarged partial cross-sectional view of the needle andsprue bushing, and internal and external tools of FIG. 8;

FIG. 10 is a cross-sectional view of the sprue bushing;

FIG. 11 is an internal view of the sprue bushing;

FIG. 12 is a side view of the needle;

FIGS. 13 a-d are illustrations of the internal mold tool showing thesprue bushing receiving opening and cooling channels formed therein;

FIG. 14 illustrates one embodiment of a polymer injection system for usewith the DIMC station;

FIG. 15 illustrates one mode of operation of the DIMC station in whichmultiple closures are molded onto respective cartons in a single cycleof operation; and

FIGS. 16-19 illustrate an exemplary closure formed in accordance withthe present invention, in which FIG. 19 illustrates the exemplaryclosure formed on a carton that has been formed, filled and sealed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describedpresently preferred embodiments with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentsillustrated.

Referring to the figures and in particular to FIG. 1, there is shown aform, fill and seal machine 10 including a direct injection moldingclosure station 12 embodying the principles of the present invention. Ina typical form, fill and seal machine 10, various stations arepositioned along the machine 10 to effect carton erection, carton bottompanel folding and sealing, sterilization, product filling, and top panelfolding and top flap sealing. One such machine is disclosed in U.S. Pat.No. 6,012,267, to Katsumata, which patent is commonly assigned herewithand is incorporated herein by reference. A filling station 11,sterilization system 15 and sealing station 17 are illustrated in FIG.1.

The direct injection molding station 12 (hereinafter referred to as“DIMC station”) is located between the carton magazine/erection station14 and a carton loader 16. However, as will be recognized by thoseskilled in the art, the station 12 can be positioned at a variety oflocations along the machine all of which locations are within the scopeof the present invention.

Referring now to FIGS. 3 through 14; there is shown one embodiment ofthe molding components of the DIMC station 12 in accordance with thepresent invention. As set forth above, in this embodiment, the DIMCstation 12 is positioned between the carton magazine/erection station 14and the carton loader 16 which further conveys the erected cartons Ctoward the bottom forming mandrels 18 of the filling machine 10.

The DIMC station 12 includes a frame 20, a polymer injection system 22,a needle 24, and a sprue bushing 26. The station 12 further includes aninternal tool or mold 28, a mandrel 30, a mandrel cap 32 mounted to themandrel 30, external tools 34 a,b and a press mechanism 36.

The frame 20 is provided for structure and for mounting the systemcomponents to the machine 10. The frame 20 supports the mandrel 30 whichlocates the top T of the carton C, a pocket or channel 38 adapted toreceive and support the internal tool or mold 28, an angled passageway40 for the sprue bushing 26 and coolant channels 42. Coolant is suppliedto the mold tools 28 and 34 a,b from a coolant supply (not shown).

The polymer injection system 22 is that portion of the DIMC station 12that receives the polymer in a solid form, such as in pellet P form,liquefies the polymer and tranports it to the closure mold tools 28 and34 a,b. A contemplated polymer injection system 22, illustrated in FIGS.4-14, includes a screw-type conveyor or extruder 50 that is positionedin a cylinder 52. Raw polymer P is fed into a hopper 54 at an upstreamend of the screw cylinder 52. The screw 50 rotates and heating elements56 positioned around the cylinder 52 elevate the temperature of thepolymer. In a preferred embodiment, the heating elements 56 areelectrically powered.

The torsional forces applied by the screw 50 and the energy transferredby the heating elements 56 liquefy the polymer. At an outlet end 58 ofthe screw cylinder 52, the now liquefied polymer flows through atransfer conduit 57, a non-return valve, preferably a check valve 59,and into a charging cylinder 60 having a pressurized space 62.

The charging cylinder 60 includes a reciprocating charging piston 64.The charging cylinder 64 is in opposing relation to and in flowcommunication with an injection cylinder 68. A non-return valve,preferably a check. valve, 70 is positioned at the outlet of thecharging cylinder 60, between the charging and injection cylinders 60,68. The check valve 70 permits flow of polymer from the chargingcylinder 60 to the injection cylinder 68, but prevents reverse flow(i.e., from the injection cylinder 68 to the charging cylinder 60).

A longitudinal axis A_(i) of the injection cylinder 68 is orientedsubstantially aligned with a longitudinal axis A_(c) of the chargingcylinder 60. That is, in the exemplary injection system 22, theinjection cylinder 68 and the charging cylinder 60 are in opposed oropposing relation to one another. As will be discussed below, thisarrangement, in conjunction with the low operating pressure of theinjection system 22, permits in-line, direct molding of the closures Sonto the container material or carton C.

A compression stroke (i.e., injection stroke) of the charging piston 64,as indicated by the arrow at 72, urges the liquefied polymer into theinjection cylinder 68. Likewise, a compression stroke of the injectionpiston 73, as indicated by the arrow at 74, urges the liquefied polymerout of the injection cylinder 68 through an injection outlet conduit 76and through a control valve 78. Referring to FIGS. 8 and 9, in a currentembodiment of the DIMC station 12, the injection outlet conduit 76 is inflow communication with and formed as part of the sprue bushing 26, andthe needle 24 reciprocates or moves within the sprue bushing 26 to serveas a control valve 78.

Referring again to FIG. 14, the charging piston 64 is actuated by asecondary or driving piston/cylinder arrangement 84 that is operablyconnected to the charging piston 64. The injection piston 73 is alsoactuated by a secondary or driving piston/cylinder arrangement (anoperating piston/cylinder arrangement) 86. The operating cylinder 86includes a stop 88 to prevent over stroke of the injection piston 73.This arrangement permits precise control of the amount of liquefiedpolymer that is expelled from the injection cylinder 68.

As provided above, this system 22 utilizes low pressure to move or expelthe liquefied polymer from the injection cylinder 68 to the mold cavity44. Such a low pressure system provides numerous advantages over knownhigh pressure injection systems. For example, the present low pressuresystem permits directly molding the closure S onto the paperboard cartonC substrate by injection molding techniques. This was previouslyobserved to be impractical with conventional high pressure injectionmolding systems. A low pressure injection molding system similar to theone described above is disclosed in International Appln. No.PCT/SE96/01191 (WO 97/11829), published 3 Apr. 1997. In a presentembodiment, the injection pressure is about 600 bar to about 1000 bar,and preferably about 800 bar. Polymers usable for this direct moldingapplication include any of various food-use approved materials, such aslow density polyethylene (LDPE) and linear low density polyethylene(LLDPE). A preferred operating temperature for the liquefied polymer isabout 200° C., and a preferred operating temperature for the mold tools28 and 34 a,b is about 25° C.

In operation of the polymer injection system 22, pellets P are fed tothe hopper 54 and into the screw cylinder 52. As the screw 50 rotatesand energy in the form of heat is transferred to the cylinder 52 by theheating elements 56, the polymer liquefies. The polymer exits the screwcylinder 52 and flows through the check valve 59 into the pressurizedspace 62 in the charging cylinder 60. The liquefied polymer istemporarily stored in the pressurized space 62 during the compression orinjection stroke 74 of the injection piston 73, during which time thecheck valve 59 closes as a result of the increase in pressure in theinjection cylinder 68. In addition, during the injection piston 73compression stroke 74, the charging piston 64 returns to thenon-compression position. This results in a lower pressure in thecharging cylinder 60, which allows the check valve 59 to open andpolymer to flow from the screw cylinder 52 into the charging cylinder60.

Upon return of the injection piston 73 to the non-injection (i.e.,non-compression) position, the charging piston 64 moves material fromthe pressurized space 62 to the injection cylinder 68. The increasedpressure in the charging cylinder 60 closes the check valve 59, thuspreventing reverse flow into the screw cylinder 52. As the injectionpiston 73 moves through the compression or injection stroke 74, thecharging piston 64 returns to its non-charging (non-compression)position. In this manner, the screw 50 continuously rotates urging theliquefied polymer forward, which is temporarily stored in the pressuredspaced 62 of the charging cylinder 60 during the compression (injection)stroke 74 of the injection piston 73. This arrangement reduces oreliminates dead spots, such as stagnant regions, within the injectionsystem 22.

The present injection system 22 essentially defines three pressureregions. A first, substantially constant pressure region is defined bythe screw cylinder 52 up to about the check valve 59. A second, alsosubstantially constant pressure region, is defined by the chargingcylinder 60, charging piston 64 and check valves 59 and 70. A thirdpressure region, which is a variable (high) pressure region is definesby the injection cylinder 68 and piston 73, the check valve 70 and theflow path through the sprue bushing 26, past the needle 24 up to andincluding the mold cavity 44.

The needle 24 is positioned within the sprue bushing 26 and serves tocontrol the flow of polymer into the mold cavity 44. The needle 24reciprocates within the sprue bushing 26 and rises off of a seat 75 onthe internal mold tool 28. The needle 24 includes an internal heater 90to control the polymer temperature and maintain the polymer in aflowable state as it is injected into the mold cavity 44. As providedabove, the sprue bushing 26 provides a flow conduit from the injectioncylinder 68 to the mold cavity 44. Referring to FIGS. 10 and 11, thesprue bushing 26 is formed having a lobed internal passageway 92. Thelobes define centering spines the maintain the needle 24 centered in thesprue bushing 26. In a present embodiment, the lobed passageway 92 andspines 93 are formed at about the terminal end of the sprue bushing 26.This arrangement also provides increased control of the flow of polymerto the mold cavity 44. In a current embodiment, the sprue bushing 26 hasa three-lobed passageway 92. Other configurations of the internalpassageway are within the scope of the present invention.

The internal and external tools 28 and 34 a,b form the inner and outer(relative to the carton) surfaces of the mold cavity 44. The internal ormale tool 28 is stationary, as is the sprue bushing 26, and is providedwith a sealed connection to the sprue bushing 26. The internal tool 28is rigidly mounted to the mandrel 30 by a plurality of fasteners 94,such as the illustrated threaded bolts. As can be seen from FIG. 10, thesprue bushing 26 includes, in addition to the lobed passageway 92,inwardly tapered surfaces, as indicated at 96, that provide an aligningpath for the needle 24. The internal tool 28 further includes a bore 98for receiving the sprue bushing 26 and a gate 100 through which theliquefied polymer flows into the cavity 44. Coolant channels 102 areformed in the internal tool 28 to cool the tool and the polymer afterthe polymer is injected into the cavity 44 to form the closures S. In acurrent embodiment, as seen in FIGS. 13 b,c the coolant channels 102 inthe internal tool 28 are formed to define a V-shaped flow channel orflow path 104. This configuration provides a high heat transfer rate anda large heat transfer area to provide for increased heat transfer in therelatively small and limited area.

A pair of external or female tools 34 a,b are used to compress thecarton C against the internal tool 28. The external tools 34 a,b aremounted to the press mechanism 36 to provide this compression. The pressmechanism 36 provides for two-directional movement of the external tools34 a,b. One direction of movement is toward and way from the internaltool 28. The other direction of movement moves the external tool halves34 a and 34 b toward and away from one another. When the external tools34 a,b are pressed against one another and pressed against the internaltool 28, the tools 28 and 34 a,b form the mold cavity 44 into which thepolymer is injected. In a present embodiment of the DIMC station 12, thepress 36 applies a pressure of about 5000 pounds to about 7000 poundsbetween the internal and external tools 28 and 34 a,b. As will berecognized by those skilled in the art, this is considerably less thanthe pressure needed in known injection molding systems which can be ashigh as 10 to 15 tons.

The two-directional movement is provided so that the external tools 34a,b can be withdrawn or moved away from the molded closure S (the firstdirection away from the carton C), and so that the closure can releasefrom the mold tools 28 and 34 a,b. The two sections 34 a and 34 b of thetwo-piece external tool separate from one another for ready release ofthe closure S after molding, without damage to the molded part.

Like the internal tool 28, the external tools 34 a,b include coolingchannels 106 for providing coolant to the tools 34 a,b during and afterpolymer injection. The external tools 34 a,b also include mounting holes110 for mounting the tools 34 a,b to the press mechanism 36. Themounting and movement of the external tools 34 a,b relative to oneanother and relative to the internal tool 28 are more fully discussed inInternational Application Nos. PCT/SE97/01594 (WO98/18608) andPCT/SE97/01596 (WO98/18609).

The internal tool 28 is mounted to the mandrel 30. The mandrel 30 is thesupport member onto which the carton C is inserted during closure Sformation. The mandrel 30 is rigidly mounted to, or formed as a part ofthe frame 20 and supports the internal tool 28 against hydrostaticforces induced by the injection of the polymer. The internal andexternal tools 28 and 34 a,b include mounting holes 110, 112 andaligning openings 114 that are used to properly mount the tools 28 and34 a,b to their respective supporting members and to properly align thetools 28 and 34 a,b relative to each other.

During set up of the machine 10, the external tools 34 a,b are mountedto the press mechanism 36 by, for example, threaded bolts 116 or thelike. The external tools 34 a,b are positioned in the “closed” state,which is that state in which the tools 28 and 34 a,b are ready forpolymer injection. With the internal tool 28 set on the external tools34 a,b, the aligning pins 118 are inserted through the internal toolopenings 114 and into the external tools 34 a,b. In this manner, thetools 28 and 34 a,b are set or aligned for proper closure S molding.

The frame 20 portion is positioned in the machine 10 frame until theinternal tool 28 is aligned with the channel or pocket 38 formed in themandrel cap 32 for receiving the tool 28. The internal tool 28 is thenfastened to the mandrel cap 32 by, for example, threaded bolts 120 andthe frame 20 is fastened to the machine 10 frame. The aligning pins 118are then removed to permit freely moving the external tools 34 a,b.

As can be seen from FIGS. 8-9, in the present DIMC station 12, polymeris injected into the mold cavity 44 from internally of the carton C.That is, when the carton C is positioned with the appropriate top Tpanel between the internal and external tools 28 and 34 a,b, and thepress mechanism 36 is closed, the interface of the sprue bushing 26 andthe internal tool gate 100 is at a position that is internal to thecarton C. this is made possible by the horizontal orientation of thecarton C. In this manner, the polymer flow path is from the internalportions of the closure S to the external portions of the closure S.Essentially, molding takes place from an internal region of the erectedcarton.

This arrangement provides a number of benefits, one such benefit beingthat any gate vestige or extraneous polymer that remains from themolding operation (generally that portion of the polymer where thepolymer is introduced into the mold cavity) is not visible to theconsumer, but is instead internal to the container. This enhances theoverall appearance of the package because this vestige is typically notan aesthetically designed piece, but rather is a remnant of the moldingprocess. Thus, forming this gate vestige at an internal portion of theclosure locates it in an area not normally viewed by a consumer.

A further benefit of this arrangement is that the sprue bushing 26 mateswith the stationary internal tool 28. Thus, those portions of the system22 that deliver the polymer to the mold cavity 44 are stationary. Thiseliminates the need to move the internal tool 28 (and the polymerdelivery portions of the system 22), thus reducing the opportunity formisalignment of the tools 28 and 34 a,b.

As will be recognized by those skilled in the art from a study of thefigures and the present description, polymer flows in a straight line,between the charging and injection cylinders 60, 68, and after expulsionfrom the injection cylinder 68 to the gate 100 and into the mold cavity44 (i.e., through the sprue bushing 26 and gate 100 and into theinternal tool 28). This straight-line arrangement eliminated dead spotsin the injection system 22, resulting in less degradation of polymer.

In addition, the mandrel 30 and mandrel cap 32 are configured to fittightly inside of the carton C to guide and accurately locate theprecise injection location (on the carton top panel or flap) withrespect to the molding tools 28 and 34 a,b. This arrangement assuresaccurately locating (±0.5 mm) the carton C between the molds 28 and 34a,b, which makes it possible to encapsulate any uncoated edge of thepackaging material that may be present at, for example, an opening.

As will be recognized by those skilled in the art, in conventionalclosure application techniques, the carton C is provided with apre-punched or pre-formed opening into which the closure is fitted andsubsequently sealed to the carton. The edges around the this area areuncoated in that the opening is formed after manufacture of thecomposite or laminate structure of the carton material.

Although it is anticipated that cartons with such pre-formed openingswill be used with the DIMC station 12, it is also anticipated thatnon-pre-formed material may also be used and that the opening can beformed as part of or integrated with the direct injection moldingprocess. To this end, the present process molds a closure S directlyonto the carton C while encapsulating the uncoated opening edges E ofthe carton C. This results in an improved appearance of the carton C andincreased hygiene as a result of the encapsulated, unexposed, uncoatededge E. Accurately locating the carton C on the mandrel 30 also greatlyreduces or eliminates any potential damage to the tooling 28 and 34 a,bfrom the packaging material.

The present configuration using alignment pins 118 to align the tools 28and 34 a,b permits the use of very small tolerances in the internal andexternal tools 28 and 34 a,b. In addition, because the alignment pins118 are placed and removed when the tools 28 and 34 a,b are stationaryand only after they are positioned relative to one another, precisealignment of the tools 28 and 34 a,b is simplified. This improvesclosure S quality and molding location accuracy, and further preventsdamage to the tools 28 and 34 a,b during operation.

The sealing connection between the sprue bushing 26 and the internaltool 28 is on cylindrical surfaces, as indicated at 122, with axialclearance for the end of the sprue bushing 26. To this end, moltenpolymer is container and thermal expansion of the sprue bushing 26 isaccommodated without stressing the internal tool 28.

The present station uses an arrangement of compact cooling channels 102and 106 which, along with the alignment holes 114 in the internal tool28, minimizes the size of the internal tool 28. Minimizing the size ofthe internal tool 28 maximizes the moment of inertia of the mandrel 30cross-section and thus increases its stiffness. The stiffness of themandrel 30 is critical to control the thickness of thin sections of theclosure S which, as will be recognized by those skilled in the art, arecritical to the function of the closure S. For example, (as will bedescribed below) if the closure is molded with a membrane or likefrangible member, the thickness (or thinness) of the frangible membermust be tightly controlled to assure that the break occurs at a precise,predetermined location. The same may also be true for other portions ofthe closure including other tamper-evidence features.

As set forth above, the internal tool 28 includes a V-shaped coolingchannel 102. This maximizes heat removal from the internal tool 28,resulting in shorter cycle times, further supporting the high throughputof molded closures S necessary to meet the high speed operation ofpresent form, fill and seal packaging machines.

In one contemplated method, a carton C blank is fed from the cartonmagazine 14. The carton C, in this form, has the side seal formed, andthe top and bottom panels are unsealed and folded flat. The carton C ispicked from the magazine 14 and is erected into a tubular form (as shownin FIG. 3 loaded onto the mandrel 30). Referring to FIGS. 1 and 2, thetubular form carton C is placed on a conveyor loader 130 and transferredto a conveyor 132. The conveyor 132 moves the carton C to the DIMCstation 12. A molder loader 134 transfers the cartons C from theconveyor 132 to the station 12. The tubular cartons C, which areoriented horizontally on the DIMC station 12 (i.e., lying on a side) arepositioned on the mandrels 30. The press mechanism 36 closes theexternal tools 34 a and b to one another and to the internal tool 28 andprovides the necessary load or pressure to maintain the mold closedduring polymer injection.

The injection system 22, which is substantially constantly in operation,is then actuated by a compression stroke 74 of the injection piston 73,and liquefied polymer is expelled from the injection cylinder 68,through the sprue bushing 26 and past the needle 24. This forces theneedle 24 to rise off of the seat 75 of the internal tool 28 andliquefied polymer fills the mold cavity 44. The edges E of the opening Oin the carton C are encapsulated as the liquefied polymer fills the moldcavity 44. This also bonds the liquefied polymer to the polymericcoating of the packaging material.

Coolant flowing through the cooling channels 102 and 106 cools theclosure S and maintains the tools 28 and 34 a,b within a predeterminedtemperature range. The press mechanism 36 then opens, separating theexternal tools 34 a and 34 b and drawing them away from the internaltool 28. The finished closure S is then released from the mold. Thecarton C, with the closure S molded thereon is removed from the mandrel30 and placed in a conveyor 136. The conveyor 136 carries the cartonsand places them in shuttles 138. The shuttles 138 feed the cartons C tomandrel loaders 140 for bottom panel folding and sealing. This portionof the process (the placement on the bottom forming mandrels, bottompanel folding and sealing) is well-known in the art Subsequent to bottompanel sealing, the cartons C are moved through the remainder of theform, fill and seal machine 10.

FIG. 15 illustrates one arrangement in which the DIMC station 12 isoperated to form closures S on four cartons C in a single cycle ofoperation. In this arrangement, cartons C1-C4 are loaded from respectivemagazines 14 onto the conveyor 132. The conveyor 132 transports thatcartons C1-C4 to one of four DIMC stations 12-1 through 12-4. Theclosures S are molded onto the cartons C1-C4 and the cartons areconveyed to the shuttles 138-1 through 138-4 for further processing asdescribed above.

One contemplated closure S formed in accordance with the present processis illustrated in FIGS. 16-19. As can be seen from the figures, theclosure S includes a bottom flange portion 176 and an upstanding spout178. A cap portion 180 of the closure S is formed integral with andseparable from the flange 176. In this closure S, a projection 182extends rearwardly from the cap 180 and is configured to engage a post184 that extends upwardly from a rear of the flange 176. Preferably, therearward projection 182 includes a hook-like end 186 that engages thepost 184 to secure the cap 180 in the open position. The post 184 canextend upwardly and rearwardly to provide greater “positive” engagementby the projection 182.

As can be seen from FIG. 18, the flange portion 176 surrounds orencapsulates the material at the edge E of the opening O in which theclosure S is formed. Advantageously, this provides a high integrity,high confidence seal between the closure S and the carton C. Inaddition, because the edges E of the opening O are uncoated,encapsulating these edges E reduces or eliminates the opportunity forliquids to seep or wick into the carton material. It is desirable toreduce seepage or wicking in that this further increases the integrityof the carton/closure combination as it effects product quality. It isanticipated that this encapsulating arrangement will also enhance theshelf-life of the product, again, by increasing product quality andreducing the opportunity for compromising the integrity of the cartonand/or contaminating the product.

The closure S further includes a tamper evident portion, indicatedgenerally at 188, which, when removed, or displaced, indicates to theconsumer that the package seal may have been broken. In a presentconfiguration, the tamper-evident portion 188 includes a tab 190 that isformed integral with the cap 180 and extends to the carton C material.Preferably, as seen in FIG. 19, an end 192 of the tab 190 is also moldedto the carton C, and most preferably, is molded to the carton C spacedfrom the flange 176. In this manner, in order to access the contents ofthe carton C (i.e., open the cap 180), it is necessary to pull or removethat portion 192 of the tab 190 that is molded to the carton C. The tab190 can be formed so that the end 192 separates from the carton C.Alternately and preferably, the tab 190 can be configured having afrangible portion 194 located between the tab end 192 and the cap 180 sothat the tab 190 is broken at the frangible region 194 to open the cap180 and access the contents of the carton C. As can be seen in thecarton C illustrated in FIG. 19, the tab 190 spans from the gableportion G of the carton C to a front wall F and is under tension in thisstate. This provides further tamper evidence or indication.

The cap 180 is configured to pivot about an elongated hinge 196 toreduce the stresses associated with opening and closing the cap 180. Thecap 180 can also include a relatively flat top region, as indicated at198 to, for example, include indicia (not shown), indicating thepackaging manufacturer, dairy, bottler or the like.

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

1. A form, fill and seal packaging machine for forming, filling andsealing a carton, the machine configured to mold a closure directly ontothe carton, the machine comprising: a carton erection station, thecarton erection station adapted to receive a carton in a generally flatform and erect the flat form carton into a tubular form defining aninternal carton region; a direct injection molding station having a moldtool having an internal mold tool and an external mold tool, theinternal mold tool configured for receipt within the internal cartonregion, the internal mold tool and the external mold tool configured toreceive and clamp the carton therebetween, the direct injection moldingstation further including a polymer injection system for injectingpolymer from a location external of the carton to the mold tool, whereina closure is directly molded in place on the carton, wherein theexternal tool is configured to move between a first position in whichthe external mold tool is disengaged from the internal mold tool and asecond position in which the external mold tool is engaged with theinternal mold tool with the carton disposed therebetween, the externalmold tool being formed having first and second portions configured tomove toward one another when the external mold tool moves to the secondposition, and away from one another when the external mold tool moves tothe first position; a filling station for filling the carton; and asealing station for forming a seal on the carton.
 2. The form, fill andseal packaging machine in accordance with claim 1, wherein the internalmold tool includes cooling channels.
 3. The form, fill and sealpackaging machine in accordance with claim 2, wherein the coolingchannels are formed having a V-shaped configuration.
 4. The form, filland seal packaging machine in accordance with claim 1, wherein thedirect injection molding station includes a frame mountable to thepackaging machine, and wherein the frame includes a mandrel on which thecarton is mounted during molding of the closure.
 5. The form, fill andseal packaging machine in accordance with claim 4, wherein the internalmold tool is mounted to the mandrel.
 6. A direct injection moldingstation for use on a form, fill and seal packaging machine for forming,filling and sealing a carton, the molding station being configured tomold a closure on a predetermined portion of the carton, the moldingstation comprising: a frame; a mold tool set including a first mold tooland a second mold tool, the first mold tool carried by the frame andhaving cooling channels formed therein in flow communication withchannels formed in the frame for supplying a coolant to the coolingchannels, the second mold tool carried by the frame, the second moldtool being movable between a first position wherein the second mold toolis disengaged from the first mold tool and a second position in whichthe second mold tool is engaged with the first mold tool with the cartondisposed therebetween, the second mold tool being formed having firstand second portions configured to move toward one another when thesecond mold tool moves to the second position, and away from one anotherwhen the second mold tool moves to the first postion; a polymerinjection system including a polymer flow conduit for providing polymerfrom a location external of the carton to the mold tool set, wherein aclosure is directly molded at the predetermined portion of the carton.7. The direct injection molding station in accordance with claim 6,wherein the cooling channels in the first mold tool are formed having aV-shaped path.